Car crashes now claim more than 40,000 lives each year in the United States, a number that has slowly declined from about 50,000 per year over the last four decades. Automobile crashes are the leading cause of death among people 1 to 34 years of age, accounting for 3.4 million nonfatal injuries annually and costing an estimated $200 billion. Rates of automobile fatalities and injuries per driver and per mile driven have decreased substantially because of safer cars and roads, laws that discourage drunk driving, and other measures, but the absolute toll of automobile crashes remains high.
By the year 2025 there will be 33 million people 70 years or older in America. This segment of the population will be growing 2.5 times as fast as the total population. These senior citizens will make up the largest percentage of “slow reaction” accidents. Slowly but surely senior citizens have developed a higher accident ratio than teenagers. And also, by 2025, total costs for motor vehicle accidents in the United States will exceed 450 billion dollars. Heretofore many studies have been conducted to improve the ergonomics of a vehicle seat. For example, “Survey of Auto Seat Design Recommendations for Improved Comfort” by M. P. Reed, et al., (University of Michigan, Transportation Research Institute, Ann Arbor), 1994 contains a review of a large body of literature with emphasis on fit parameters related to anthropometric measurements, feel parameters, including pressure distribution and vapor permeability, and support parameters defined with respect to the seat posture. Particular attention is given to appropriate lumbar support.
Other studies aimed at measuring the reaction time of the driver in case of dangerous situations can be found in the following publications and Internet materials: 1) “Reaction-Time Measurement and Real-Time Data Acquisition for Neuroscientific Experiments in Virtual Environments” by J. Valvoda, et al., Aachen University (http://www.rz.rwth-aachen.de/vr/papers/MMVRJan2004.pdf); 2) Reaction Time of Drivers to Road Stimuli, Monash University Human Factors Group—Report HFR-12, Authors: T. Triggs & W. Harris, (http://www.monash.edu.au/muarc/reports/Other/hfr12.html); and 3) How the Driver Reaction Meter Works (http://www.sibtec.com/driverhowitworks.html).
U.S. Pat. No. 6,170,355 issued in 2001 to W. Fay, III discloses an easily adjustable foot-operated pedal assembly, such as a brake pedal for use in heavy equipment that can be placed in multiple positions to accommodate people of differing heights and body shapes.
The necessity for a raised under-thigh support] is mentioned in many advertisements for modern cars. For example, in “Nissan 350Z GT-MotorBar Road Test” it is stated that “a raised bolster in the middle of the seat cushion helps give extra under-thigh support for more precise operation of the pedal”. In the pamphlet entitled “Follow-Up Test: 2006 Jeep Grand Cherokee SRT8” it is stated that “the long-haul comfort is commendable too, with excellent under-thigh support and feeling of the seats wrapping around”.
Investigations show that the total stopping distance of a vehicle is made up of four components: human perception time; human reaction time; vehicle reaction time; and vehicle braking capability.
Human perception time is the time it takes a driver to see a hazard and the brain to realize that it is a hazard requiring immediate reaction. This component of stopping distance is human factors and as such can be affected by age, tiredness, alcohol, and concentration levels. Once the brain realizes danger, the human reaction time is the time it takes to move the foot from the accelerator to the break pedal and then to depress the pedal. The movement time from the accelerator to the brake is approximately 500 ms (according to the University of Iowa).
Heretofore many studies have been conducted in order to determine the response time for pressing the brake pedal. For example, an article “Response Time” by Charles C. Roberts, Jr. (http://www.croberts.com/respon.htm) describes a test apparatus that evaluates this reaction time. As soon as the light turns red on the console, the driver releases the accelerator and applies the brake. The reaction time is measured. This form of testing is often called “simple reaction time” because it is a result of a single stimulus, the red light. Reaction times are typically on the order of ¾ of a second. However, response times are more complex and can be as high as 3 to 4 seconds because response time consists of perception/decision time plus reaction time. The perception/decision time is the time it takes to view a hazard and to decide what to do about it. The reaction time is the time it takes to perform a particular function once a decision is made. The response time for removing one's hand from a hot skillet is relatively quick and is on the order of about a half second. In this example, a natural response to excessive heat bypasses visual sensors, allowing for a quicker response time. Driving an automobile requires a high degree of visual processing, which tends to extend response times. What can be gleaned from the discussions in the article is that response time is a distributed quantity because of variability in people as well as in situations that require a response. The accident reconstruction community often assumes a maximum 2.5- to 3.0-second response time. This may apply to most accidents with obvious hazards. Other accidents involving less defined or confusing hazards may result in longer response times. Other factors extending response time are age, time of day, gender, and chemical usage, suggesting that response time is typically characteristic of a particular set of circumstances encountered in an accident.
There are many other studies of response times and their usage, but none of these studies takes into account the effect of finding the most optimal physical position for the driver's leg relative to the accelerator and brake pedal.
When driving a vehicle, the driver's leg that controls the accelerator and brake pedal can be considered a biomechanical system, the model of which is shown in FIG. 1. In the context of the present invention, the part of the leg from the fulcrum point H of the heel on the vehicle floor to the knee joint KN is referred to as “leg” L; the part of the driver's leg from the point H to the point T1 of contact with the accelerator pedal 20 is referred to as “foot” FT; and the part of the driver's leg from the point KN to the pelvic floor joint PF, which is considered the a fulcrum point on the vehicle seat 22, is referred to as “thigh” TH.
FIG. 2 is a view of the driver's right leg in the direction of arrow A in FIG. 1. Two planes must be considered for analysis of the movement in which the driver's leg participates. The first plane is a plane I-I that is slightly inclined with respect to the vertical plane V-V and passes through the thigh TH and leg L, i.e., the plane that passes through the joints PF, KN, and H′ (where H′ is a heel joint (FIGS. 1 and 2). The plane I-I corresponds to the unrestrained position of the leg during normal driving with the foot PT on the accelerator pedal 20. The second plane is plane II-II which passes through the same joints when the foot FT is on the brake pedal 24. The position of the leg in plane II-II is shown by broken lines.
Let us consider movements of the driver's leg during when one drives a car with an automatic gear box wherein two pedals, i.e., the accelerator pedal and the brake pedal, are used to control the car. Although in reality, these movements are more complicated, in a simplified form they can be considered as the following two modes.
In the first mode, let us assume that for the initial position of the leg, the foot FT is on the accelerator pedal 20. When braking is needed, the driver with relatively short legs first slightly raises the foot FT from the floor F so that the heel is disconnected from point H and the leg is shifted sidewise to the brake pedal 24. In this movement the entire leg is raised relative to the point PF as a fulcrum. The driver then turns the entire leg relative to the plane I-I to the plane II-II and moves the leg down in order to press on the brake pedal 24.
In the second mode, which is more typical for a driver with relatively long legs, in order to brake from the position on the accelerator pedal 20, the driver merely turns the foot FT relative to the point H.
In reality, the aforementioned movements are more complicated and may comprise a combination of both movements simultaneously. In the context of the present patent application, the movement of the foot from the accelerator pedal to the brake pedal also includes the movement of pushing on the brake pedal until actual initiation of the brakes, i.e., to the moment when the brake lights are ignited.
It is important to consider the aforementioned movements with regard to the time of braking. It has been experimentally proven by the inventor that when a human being accomplishes braking movements on the basis of subconscious reflexes, the aforementioned movements are not at all optional. In other words, there exists a certain unnatural position of the pedal-controlling leg that can provide a more optimal breaking condition, i.e., the condition that allows shortening of the braking time and hence of the braking path.
To provide the most optimal position of a driver's right leg in order to shorten the momentum for movement of the feet from the accelerator pedal to the brake pedal and to subsequently press the brake pedal, the inventor herein developed a special under-thigh pillow that can be used for supporting and fixing the driver's right leg in the aforementioned optimal position.
The aforementioned under-thigh pillow is a subject of pending U.S. patent application Ser. No. 11/509,376 which was filed by the same applicant on Aug. 24, 2006 and which is incorporated herein by reference.
The use of the aforementioned under-thigh support is justified only if the aforementioned under-thigh support is installed and fixed in a predetermined position that depends on specific anthropometric data of each individual driver. In other words, the most optimal position of the under-thigh support of the aforementioned patent application will be different for people of different builds.